Manufacture of photographic films.



EDWIN nnannnnsnacnn, or rmoN-nEs-vosens, FRANCE.

No Drawing.

MANUFACTURE PHOTOGRAPHIG FILMS.

Patented use. 21, 1911.

To all whom 'it may concern:

Be it known that'l, Eowm BnAnnnN- nausea, a chemist, of Thaon-Les-Vosges,

, Vos es, France, have invented a new and use 111 Improved. Manufacture of Photographic Films, which is fully set forth in the following specification.

This invention relates to a process by means of which it is possible to make sensitive to the light, cellulosic films obtained from watersolution, more particularly cellu-' losic films obtained by regenerating the cellulose of-a Water solution of celluloslc xanthate of sodium (viscose). The films thus obtained can be used in photography, for kinematographic stereoscopic purposes, etc., either as ositive or as negative films.

he process of manufacture is as follows: The cellulose -filmsjust mentioned are first of all'dipped-into a bath of water, so as to obtain a swelling of the said films. In that state the are at once dipped into a bath of a chlori bromid or iodld, as is generally done in photography, preferably using either.

chlorid of sodium or iodid of potassium. Owing to the particular state of the film at the moment of its immersion into the bath, on account of the swellingproduced by the water, the salt penetrates into the film in stead of merely forming a superficial layer. It is roperly impregnated when removed from the chlorid, bromid or iodid bath."

It will be understod that the'swelling required for the impregnating just'meritioned,

6 could be obtainedwlthout using the waterv bath, but using a water solution of thechlm rid, bromid or iodidi" In that single bath the film would become swollen and impregnoted with chlorid,-bromid or iodid'.

so After removin' it from the chlorid, bro-' mid or iodid bath, the film can be dried or immediately d1pped into a bath of silver salt such as nitrateof silver, similar to that used in photo phy. After being removed fromthat bat the film could be subjected to. the action of any suitablebath used in photograhy, either in order to increase its zensitiveness, or for giving itsp'ecial properies. .50 Itgoes without saying that the order in which the film passes into the. successive baths is not absolutely essential, this order could-be modified according'to the process emplo ed. In the same way, it is obvious that, nstead of immersing the films in the 'spbstance capable of rendering the film sensltivefto light, fdr instance, salts of. gold, salts of iron (ferro-cyanids) etc, and, gen-- erally, any saltsused in photography; The impregnation would take place in the same conditions, and the result desired, namely the production of a sensitive film without gelatin or any other method of fixing, would be obtained. Heat no longer has any effect onthe photographic impressions obt-ained', and no separation can take place such as often happens with all sensitive papers or plates, in which the sensitive portion is merely a superficial onc' and is not impregnated in the massof the support.

It will be understood that it is possible to fix cellulose films thus obtained, to a suitable su port, for instance glass or paper. The fixing would be effected by glue, either soluble or insoluble in water, according to the purposes desired, and the said fixing could be one either before the sensitizing of the film or after.

Cellulos'esheets could be treated eitherby treating'a continuous band, 'or by treating sheets cut to the desired size.

'Having now'iparticularly described and ascertained the nature of my said invention and in what manner the same is to be 'performed, I declare that what I claim is .1.- The hereinl,'described process of sensitizing film's, which consists in placing a film in a liquid bath, allowing the film toremain in said bat-h until the film has swelled,

and then impregnating thefilm with sensitizin substances.

2. %he herein described process of" sensitizing films, which consistsin placing a cellulosic film in a liquid bath, allowing the film to "remain in' said bath until the film has swelled, and then impregnating the film with sensitizing substances.

3. The herei described process of sensitizing films, w ich consists n placing a cellulosic fihn in a bath of a huloid sult allowa silver Hall, and further treating the film 10 ing the film to remain in said bath until the for photographic purposes. fihn has swelled, and then impregnatlng the In testimony whereof I have signed this film with sensitizing substances. specification in'the presence of two subscrib 4. The herein described process of sensi-. ing \\'-'itnesses. tizing films, which consists in placing a cel- EDWIN BRANDENBERGER. lulosic filmin a bath of a haloid salt, allow- Witnesses:

ing the film to remain in said bath until the EMILE LUBRET,

film is swelled, placing the film in 9. bath of H. C. COXE. 

